Configure log4net

Before you begin, you’ll need:

  • log4net 2.0.8 or higher
  • .NET Core SDK version 2.0 or higher
  • .NET Framework version 4.6.1 or higher
Add the dependency to your project

If you’re on Windows, navigate to your project’s folder in the command line, and run this command to install the dependency.

Install-Package Logzio.DotNet.Log4net

If you’re on a Mac or Linux machine, you can install the package using Visual Studio. Select Project > Add NuGet Packages..., and then search for Logzio.DotNet.Log4net.

Configure the appender

You can configure the appender in a configuration file or directly in the code. Use the samples in the code blocks below as a starting point, and replace them with a configuration that matches your needs. See log4net documentation 🔗 to learn more about configuration options.

For a complete list of options, see the configuration parameters below the code blocks.👇

Option 1: In a configuration file
<log4net>
    <appender name="LogzioAppender" type="Logzio.DotNet.Log4net.LogzioAppender, Logzio.DotNet.Log4net">
    	<!-- 
		Required fields 
	-->
	<!-- Your Logz.io log shipping token -->
	<token><<LOG-SHIPPING-TOKEN>></token>
			
	<!-- 
		Optional fields (with their default values) 
	-->
	<!-- The type field will be added to each log message, making it 
	easier for you to differ between different types of logs. -->
    	<type>log4net</type>
	<!-- The URL of the Logz.io listener -->
    	<listenerUrl>https://<<LISTENER-HOST>>:8071</listenerUrl>
        <!--Optional proxy server address:
        proxyAddress = "http://your.proxy.com:port" -->
	<!-- The maximum number of log lines to send in each bulk -->
    	<bufferSize>100</bufferSize>
	<!-- The maximum time to wait for more log lines, in a hh:mm:ss.fff format -->
    	<bufferTimeout>00:00:05</bufferTimeout>
	<!-- If connection to Logz.io API fails, how many times to retry -->
    	<retriesMaxAttempts>3</retriesMaxAttempts>
    	<!-- Time to wait between retries, in a hh:mm:ss.fff format -->
	<retriesInterval>00:00:02</retriesInterval>
	<!-- Set the appender to compress the message before sending it -->
	<gzip>true</gzip>
	<!-- Uncomment this to enable sending logs in Json format -->
	<!--<parseJsonMessage>true</parseJsonMessage>-->
	<!-- Enable the appender's internal debug logger (sent to the console output and trace log) -->
	<debug>false</debug>
	<!-- If you have custom fields keys that start with capital letter and want to see the fields 
	with capital letter in Logz.io, set this field to true. The default is false 
	(first letter will be small letter). -->
	<jsonKeysCamelCase>false</jsonKeysCamelCase>
	<!-- Add trace context (traceId and spanId) to each log. The default is false -->
	<addTraceContext>false</addTraceContext>
    <!-- Use the same static HTTP/s client for sending logs. The default is false -->
	<UseStaticHttpClient>false</addTraceContext>
    
    </appender>
    
    <root>
    	<level value="INFO" />
    	<appender-ref ref="LogzioAppender" />
    </root>
</log4net>

Add a reference to the configuration file in your code, as shown in the example here.

Code sample
using System.IO;
using log4net;
using log4net.Config;
using System.Reflection;

namespace dotnet_log4net
{
    class Program
    {
        static void Main(string[] args)
        {
            var logger = LogManager.GetLogger(typeof(Program));
            var logRepository = LogManager.GetRepository(Assembly.GetEntryAssembly());

            // Replace "App.config" with the config file that holds your log4net configuration
            XmlConfigurator.Configure(logRepository, new FileInfo("App.config"));

            logger.Info("Now I don't blame him 'cause he run and hid");
            logger.Info("But the meanest thing he ever did");
            logger.Info("Before he left was he went and named me Sue");

            LogManager.Shutdown();
        }
    }
}
Option 2: In the code
var hierarchy = (Hierarchy)LogManager.GetRepository();
var logzioAppender = new LogzioAppender();
logzioAppender.AddToken("<<LOG-SHIPPING-TOKEN>>");
logzioAppender.AddListenerUrl("<<LISTENER-HOST>>");
// <-- Uncomment and edit this line to enable proxy routing: --> 
// logzioAppender.AddProxyAddress("http://your.proxy.com:port");
// <-- Uncomment this to enable sending logs in Json format -->  
// logzioAppender.ParseJsonMessage(true);
// <-- Uncomment these lines to enable gzip compression --> 
// logzioAppender.AddGzip(true);
// logzioAppender.ActivateOptions();
// logzioAppender.JsonKeysCamelCase(false);
// logzioAppender.AddTraceContext(false);
// logzioAppender.UseStaticHttpClient(false);
logzioAppender.ActivateOptions();
hierarchy.Root.AddAppender(logzioAppender);
hierarchy.Root.Level = Level.All;
hierarchy.Configured = true;
Code sample
using log4net;
using log4net.Core;
using log4net.Repository.Hierarchy;
using Logzio.DotNet.Log4net;

namespace dotnet_log4net
{
    class Program
    {
        static void Main(string[] args)
        {
            var hierarchy = (Hierarchy)LogManager.GetRepository();
            var logger = LogManager.GetLogger(typeof(Program));
            var logzioAppender = new LogzioAppender();
            
            logzioAppender.AddToken("<<LOG-SHIPPING-TOKEN>>");
            logzioAppender.AddListenerUrl("https://<<LISTENER-HOST>>:8071");
            // <-- Uncomment and edit this line to enable proxy routing: --> 
            // logzioAppender.AddProxyAddress("http://your.proxy.com:port");
            // <-- Uncomment this to enable sending logs in Json format -->  
            // logzioAppender.ParseJsonMessage(true);
            // <-- Uncomment these lines to enable gzip compression --> 
            // logzioAppender.AddGzip(true);
            // logzioAppender.ActivateOptions();
            // logzioAppender.JsonKeysCamelCase(false)
            // logzioAppender.AddTraceContext(false);
            // logzioAppender.UseStaticHttpClient(false);
            logzioAppender.ActivateOptions();
            
            hierarchy.Root.AddAppender(logzioAppender);
            hierarchy.Configured = true;
            hierarchy.Root.Level = Level.All;

            logger.Info("Now I don't blame him 'cause he run and hid");
            logger.Info("But the meanest thing he ever did");
            logger.Info("Before he left was he went and named me Sue");

            LogManager.Shutdown();
        }
    }
}
Parameters
Parameter Description Default/Required
token Your Logz.io log shipping token securely directs the data to your Logz.io account. Replace <<LOG-SHIPPING-TOKEN>> with the token of the account you want to ship to. Required
listenerUrl Listener URL and port. Replace <<LISTENER-HOST>> with the host for your region. For example, listener.logz.io if your account is hosted on AWS US East, or listener-nl.logz.io if hosted on Azure West Europe. The required port depends whether HTTP or HTTPS is used: HTTP = 8070, HTTPS = 8071. https://listener.logz.io:8071
type The log type, shipped as type field. Used by Logz.io for consistent parsing. Can’t contain spaces. log4net
bufferSize Maximum number of messages the logger will accumulate before sending them all as a bulk. 100
bufferTimeout Maximum time to wait for more log lines, as hh:mm:ss.fff. 00:00:05
retriesMaxAttempts Maximum number of attempts to connect to Logz.io. 3
retriesInterval Time to wait between retries, as hh:mm:ss.fff. 00:00:02
gzip To compress the data before shipping, true. Otherwise, false. false
debug To print debug messages to the console and trace log, true. Otherwise, false. false
parseJsonMessage To parse your message as JSON format, add this field and set it to true. false
proxyAddress Proxy address to route your logs through. None
jsonKeysCamelCase If you have custom fields keys that start with a capital letter and want to see the fields with a capital letter in Logz.io, set this field to true. false
addTraceContext If want to add trace context to each log, set this field to true. false
useStaticHttpClient If want to use the same static HTTP/s client for sending logs, set this field to true. false

Custom fields

You can add static keys and values to be added to all log messages. These custom fields must be children of <appender>, as shown here.

<appender name="LogzioAppender" type="Logzio.DotNet.Log4net.LogzioAppender, Logzio.DotNet.Log4net">
  <customField>
    <key>Environment</key>
    <value>Production</value>
  </customField>
  <customField>
    <key>Location</key>
    <value>New Jerseay B1</value>
  </customField>
</appender>

Extending the appender

To change or add fields to your logs, inherit the appender and override the ExtendValues method.

public class MyAppLogzioAppender : LogzioAppender
{
  protected override void ExtendValues(LoggingEvent loggingEvent, Dictionary<string, object> values)
  {
    values["logger"] = "MyPrefix." + values["logger"];
    values["myAppClientId"] = new ClientIdProvider().Get();
  }
}

Change your configuration to use your new appender name. For the example above, you’d use MyAppLogzioAppender.

Add trace context

The Trace Context feature does not support .NET Standard 1.3.

If you’re sending traces with OpenTelemetry instrumentation (auto or manual), you can correlate your logs with the trace context. In this way, your logs will have traces data in it: span id and trace id. To enable this feature, set <addTraceContext>true</addTraceContext> in your configuration file or logzioAppender.AddTraceContext(true); in your code. For example:

using log4net;
using log4net.Core;
using log4net.Repository.Hierarchy;
using Logzio.DotNet.Log4net;

namespace dotnet_log4net
{
    class Program
    {
        static void Main(string[] args)
        {
            var hierarchy = (Hierarchy)LogManager.GetRepository();
            var logger = LogManager.GetLogger(typeof(Program));
            var logzioAppender = new LogzioAppender();
            
            logzioAppender.AddToken("<<LOG-SHIPPING-TOKEN>>");
            logzioAppender.AddListenerUrl("https://<<LISTENER-HOST>>:8071");
            // <-- Uncomment and edit this line to enable proxy routing: --> 
            // logzioAppender.AddProxyAddress("http://your.proxy.com:port");
            // <-- Uncomment this to enable sending logs in Json format -->  
            // logzioAppender.ParseJsonMessage(true);
            // <-- Uncomment these lines to enable gzip compression --> 
            // logzioAppender.AddGzip(true);
            // logzioAppender.ActivateOptions();
            // logzioAppender.JsonKeysCamelCase(false)
            // logzioAppender.UseStaticHttpClient(false);

            logzioAppender.AddTraceContext(true);
            logzioAppender.ActivateOptions();
            
            hierarchy.Root.AddAppender(logzioAppender);
            hierarchy.Configured = true;
            hierarchy.Root.Level = Level.All;

            logger.Info("Now I don't blame him 'cause he run and hid");
            logger.Info("But the meanest thing he ever did");
            logger.Info("Before he left was he went and named me Sue");

            LogManager.Shutdown();
        }
    }
}

Serverless platforms

If you’re using a serverless function, you’ll need to call the appender’s flush method at the end of the function run to make sure the logs are sent before the function finishes its execution. You’ll also need to create a static appender in the Startup.cs file so each invocation will use the same appender. The appender should have the UseStaticHttpClient flag set to true.

Azure serverless function code sample

Startup.cs ```csharp using Microsoft.Azure.Functions.Extensions.DependencyInjection; using log4net; using log4net.Repository.Hierarchy; using Logzio.DotNet.Log4net;

[assembly: FunctionsStartup(typeof(LogzioLog4NetSampleApplication.Startup))]

namespace LogzioLog4NetSampleApplication { public class Startup : FunctionsStartup { public override void Configure(IFunctionsHostBuilder builder) { var hierarchy = (Hierarchy)LogManager.GetRepository(); var logzioAppender = new LogzioAppender(); logzioAppender.AddToken(“<>"); logzioAppender.AddListenerUrl("https://<>:8071"); logzioAppender.ActivateOptions(); logzioAppender.UseStaticHttpClient(true); hierarchy.Root.AddAppender(logzioAppender); hierarchy.Configured = true; } } }


*FunctionApp.cs*
```csharp
using System;
using Microsoft.Azure.WebJobs;
using Microsoft.Extensions.Logging;
using log4net;
using MicrosoftLogger = Microsoft.Extensions.Logging.ILogger;

namespace LogzioLog4NetSampleApplication
{
    public class TimerTriggerCSharpLog4Net
    {
        
        private static readonly ILog logger = LogManager.GetLogger(typeof(TimerTriggerCSharpLog4Net));

        [FunctionName("TimerTriggerCSharpLog4Net")]
        public void Run([TimerTrigger("*/30 * * * * *")]TimerInfo myTimer, MicrosoftLogger msLog)
        {
            msLog.LogInformation($"Log4Net C# Timer trigger function executed at: {DateTime.Now}");

            logger.Info("Now I don't blame him 'cause he run and hid");
            logger.Info("But the meanest thing he ever did");
            logger.Info("Before he left was he went and named me Sue");
            LogManager.Flush(5000);

            msLog.LogInformation($"Log4Net C# Timer trigger function finished at: {DateTime.Now}");
        }
    }
}